1. The Magnetosphere and Plasmasphere CSI 769 3 rd section, Oct. – Nov. 2005 J. Guillory

2. Lecture 7 (Oct.18) Bow shock scattering; Magnetosphere structure, charged particle orbits –Advance reading: Gombosi Ch.1 & 6 (and/or Parks Ch. 4, 8 &10), Tascione Ch.4, and Sci. Am. Apr. 1991: Collisionless Shock Waves Lecture 8 (Oct. 25) Dawn-dusk electric field; gyrokinetic codes; magnetotail & current sheet –Advance reading: Gombosi Ch. 7 & 14, Parks Sec. 7.8 & 11.5), Tasc. Ch 5 Lecture 9 (Nov. 1) MHD codes & boundary conditions; parallel E-fields & precipitation; satellite diagnostics –Advance reading: Gombosi Ch. 4, Parks Sec. 7.7 In conjunction with the last topic: –Joel Fedder (NRL) is scheduled for a Space Sciences Seminar on his MHD magnetosphere code, Wed. 10/26, 3:00 p.m., 206 –Please attend.

3. Bow shock

4. Perpendicular shock

5. Oblique shock

6. waves & particles in upstream foreshock From Sagdeev & Kennel, Sci. Am. Apr. 1991

7. Foreshock region

8. Current in shock layer From G. K. Parks, Physics of Space Plasmas, AW 1991

9. Components of v along B and the shock surface, for incident & reflected particles

10. Repeated reflections from solitons near nonsteady shock From Sagdeev & Kennel, Sci. Am. Apr. 1991

11. ISEE In-situ B-field measurements across bow shock

12. Collisionless shock structure Hybrid code simulation by M. Leroy et al, GRL 8, 1269 (1981) C. S. Wu, D. Winske et al., Sp.Sci. Revws 37, 63 (1984)

13. Ion distributions near shock

14. Phase space in normal direction Electric potential structure

15. Incoming particle scattering Stochastic Injection of Energetic Particles from Bow Shock and from Tailward reconnection region Nonadiabatic because gyroradius ~ B scale-length locally Particle orbit diffusion due to field fluctuations Some particles accelerated near bow shock and magnetic reconnection regions

16. Magnetic field geometry

17. Model field topology for northward IMF IMF + dipole

18. Model field topology for southward IMF From G. K. Parks, Physics of Space Plasmas, AW 1991

19. Field line motion with southward IMF (after J. Dungey, 1961). North is DOWN in this fig. From G. K. Parks, Physics of Space Plasmas, AW 1991

20. Detail of day-side reconnection field & flows

21. Field near reconnection region (more on reconnection later)

22. Inner magnetosphere: Energetic proton density contours, showing South Atlantic anomaly

23. Mag. dipole offset from rotation axis and tilted

24. Van Allen Belts Inner belt energetic protons from cosmic ray albedo neutron decay (CRAND) and from diffusion from elsewhere. Outer belt somewhat energetic ions from solar wind injection and accelerated from ionosphere, and diffusion from elsewhere.

25. Approx. avg. contours of spatial distribution of trapped energetic protons & electrons (Van Allen, 1968)

26. NSSDC quiet-time static empirical model (AP-8) of energetic proton flux density J. D. Gaffey & D. Belitza, J. Spacecraft & Rockets 31, 172 (1994)

27. NSSDC quiet-time static empirical model (AE-8) of energetic electron flux density J. D. Gaffey & D. Belitza, J. Spacecraft & Rockets 31, 172 (1994)

28. Calculated energetic proton lifetimes (x n e ) in inner Van Allen belt under quiescent conditions R. C. Wentworth, “Pitch Angle Diffusion.. ”, Phys. Fluids 6, 431 (1963)

29. Satellite measurement of proton density vs L, during quiet and CME-arrival conditions OGO-5 measuremts R. Chappell et al, JGR 75, 50 (1970)

30. Squeezing the magnetosphere: quasistatic pressure balance estimate Ram pressure of CME arrival + IMF  v 2 vs interior particle+field pressure Increasing B produces inductive E fields and currents

31. Energy transfer from CME to magnetosphere: time delay From Tascione, after Baker et al, JGR 90, 1205 (1985)

32. Particle currents in the magnetosphere

33. Ring current reduces B at surface After CME compression of day-side magnetosphere, B horiz at R E decreases ~1 hr after sudden-commencement rise, and stays reduced for 1-3 days, gradually returning to pre-storm values. This is correlated with injection of 10- 100keV magnetotail particles into ring- current region.

34. Global magnetic change index (Tascione sec 4.7) K: integer, 0 – 9 : 3-hr average of  B, on quasi-log scale, for each of several ground locations Kp: average of K’s from 12 locations between 48 & 63 degrees latitude, averaged with local & seasonal variation filtered out

35. Dst index (Tascione p.51) Hourly avg. (from 4 low-latitude ground stations) of changes in horizontal component of B, with seasonal variations subtracted out. A measure of changes in ring-current intensity

36. AE (Auroral electrojet) index Spread between max positive & max negative changes in horizontal component of B at several auroral-latitude locations, 62.5 – 71.6 degree latitudes Global AE = maximum of the positive changes in horizontal component at any such location - maximum of the negative changes in horizontal component at any such location

37. Electric fields and more currents & plasma flows Plasma corotation-induced E field: – E = - (  x r) x B – = B o R E (R E /r) 2 (2sin e + cos  e r ) approximately, for dipole B. Inner part of earth’s magnetosphere corotates. Added to dawn-dusk E field due to solar wind

38. Model E-fields in equatorial plane

39. Collisionless plasma flow (not currents) in E perpendicular to B v D /c = E x B /B 2 (cgs), if (as usual) E (cgs) << B (G)

40. B-Field-aligned currents and fields High-conductivity acceleration-limited currents along B-lines Downstreaming charges arrive & die at dense ionosphere, producing auroral glow. Upstreaming charges from ionosphere populate plasmasphere and mag’sphere.

41. From Tascione

42. Field-aligned ion beam distributions in plasma sheet boundary layer from ISEE-1, 16 Feb 1980. (T.E. Eastman, R.J. DeCoster & L.A. Frank, in Cross-Scale Coupling in Space Plasmas

43. Velocities for steady-state polar wind with no field-aligned current S. B. Ganguli, H. B. Mitchell, & P. Palmadesso, NRL Memo Report 5673, 1985

44. Velocities (magnitude) 70 min after onset of a current of -1  A/m 2 at 1500 km S. B. Ganguli, H. B. Mitchell, & P. Palmadesso, NRL Memo Report 5673, 1985

45. Heating by these currents S. B. Ganguli, H. B. Mitchell, & P. Palmadesso, NRL Memo Report 5673, 1985

46. Particle orbits in inner magnetosphere Assumptions:  B/B is small over a gyroradius & gyroperiod Motion of the particles of interest is collisionless (except if the hit the ionosphere, where they die)

47. Charged particle orbits, static B: (for B quasistatic and gradB/ B << r g -1 ) Fast gyration about field line North-south bounce due to “magnetic mirror” force Slow east-west drift due to inhomogeneous magnetic field ExB drifts due to electric fields

48. Gyration about B-line: r g =  mv/qB (MKS units)  c = qB/  m (MKS units) or qB/mc (cgs) Sub-kHz to MHz angular frequencies (2  f):  c ~ 1.76x10 7 B(G)/  for electrons ~ 10 4 B(G) for protons

49. Scale of Proton Gyroradius & Gyrofrequency 0.1 Gr g (1 MeV) = 10 km A (  perp /  )½  ci = 1000 rad/s; f ci = 160/s.01 Gr g (1 MeV) = 100 km A (  perp /  )½  ci = 100 rad/s; f ci = 16/s t N-S ~ 1.3 s (L=2) ~50 gyroperiods

50. Adiabatic invariants General form ∫pdq 1. Magnetic moment invariant  = p perp 2 /2mB(  = qr g 2 /2c) 2. Bounce invariant J = ∫p par ds 3. Longitudinal drift invariant (L shell)

51. North-South bounce motion Determined by pitch-angle of fast velocity vector at magnetic equator, And by energy conservation. If E parallel =0, each particle’s parallel energy is converted to perpendicular energy until it has no more parallel momentum, then it reverses its parallel motion.

52. Effective magnetic mirror force When a very-small-size dipole moves along magnetic field lines of an inhomogeneous field, there is an effective “force” parallel to the field line that has magnitude & sign F parallel = -  d B/ds where s measures arclength along the magnetic field. A dipole entering a region of stronger magnetic field thus has a retarding force on it, slowing its parallel motion.

53. One may ask “How can this be? The magnetic force on a charged particle, qvxB/c, is always perpendicular to v and so can do no work on the particle if B is constant in time.” In fact, the particle kinetic energy, ½ m v z 2 + ½ m v y 2, does not change; only the partition between v z and v y changes. And this change of the direction of v is due to the fact that the particle is not exactly at the position of its guiding center, so the directions of the field lines of B at the particle are not quite the same on opposite sides of the gyro-orbit, leading to a gyro-averaged vxB force that has a parallel component.

54. The constancy of  = (½ m v perp 2 ) /B during collisionless nonrelativistic charged particle motion along B, and the constancy of ½ m v par 2 + ½ m v perp 2 = KE, mean that v par can be expressed in terms of its value at some reference point s o by ½ m v par 2 = (½ m v par 2 ) o -  (B - Bo), i. e. the parallel motion is derivable from a potential,  B. (If there is also a static electric field parallel to the magnetic field, the effective potential for parallel motion of the “dipoles” generalizes nicely to  B + q .) When B has a minimum at some reference point s o along each magnetic field line encircled (or “enhelixed”) by a particle, the collisionless parallel motion will be that of a particle in an effective potential well (remember, though, that the magnetic potential depends on the constant , which is not the same for all particles !).

55. Half of Loss-cone(s) in magnetic- equator velocity-space Shown for no parallel electric field

56. Particle turns around where ( & if) v par 2 = 0, where all the energy is converted to perpendicular energy, i. e. at B such that (½ m v par 2 ) o -  B - B o ) - q(  -  o ) = 0. This turning point equation, with the help of magnetic moment constancy (½ m v perp 2 ) /B = (½ m v perp 2 ) o /B o, specifies the turning points as where (½ m v par 2 ) o - (½ m v perp 2 ) o (B/B o - 1) - q(  -  o ) = 0.

57. When there is negligible parallel electric field this is simply B /B o = 1 + (v par 2 / v perp 2 ) o, so each trapped collisionless particle mirrors, i.e. changes its sign of parallel velocity, at a value of B/B o that depends on its pitch angle at the minimum of the magnetic field. In the reference-plane velocity space {v par o, v perp o }, one can draw a boundary for any value of B 1, such that particles with |v perp o | above the boundary will be trapped in the spatial region where B < B 1, and those with |v perp o | below the boundary can progress to higher values of B than B 1 if nothing else stops them first.

58. Loss regions in midplane velocity space(s) when there is a steady parallel E field toward the ionosphere (positive potential on field line) Positive potential occurs so as to reduce electron loss rate to the (increased) ion loss rate. Lost to ionosphere in 1 bounce trapped

59. Same thing in midplane energy space

60. Particle gyration & bounce in inner magnetosphere From T. Tascione, Intro to the Space Environment

61. Energy conservation (with E=0)  o = pitch angle at mag. Equator ( = 0) B o = field strength at mag. Equator (From G. K. Parks, Physics of Space Plasmas)

64. Charged particle longitudinal drift due to magnetic field inhomogeneity Cross-field drift of – and + particles under force F From Parks, Physics of Space Plasmas

68. Longitude-drift periods (from Parks)

69. Drift Rate (in terms of energy, mag. Moment, bounce invariant, bounce period, and L) For static magnetic dipole, with E = 0: = - (2cLR E  /e  ) (3/2 - J/4  ) with  = ∫ds/v y = N-S bounce period, and J = m ∫v y ds = bounce action integral. T. G. Northrop, in Radiation Trapped in the Earth’s Magnetic Field, B. M. McCormac, ed., Reidel 1966

70. For nonstatic dipole B without shear (but changes slow enough to preserve J and  ): = - (2c/e  )∫rd  (B/B  ){(2m(H -  B - q  ))½ [(B  /B)( ∂/∂L)(rB/B  ) + ½ r ∂B/∂L ] - ½ (2m(H -  B - q  )) -½ [2m(H -q  )r ∂lnB/∂L+ rq ∂  /∂L]} with  = electric potential and  = longitude angle. T. J. Birmingham, “Guiding center drifts in time- dependent meridional magnetic fields”, Phys. Fluids 11, 2749 (1968)

71. Ring Current from drifting, gyrating particles (Parks sec. 7.7.4, with corrections) (a) From guiding-center drifts J gc = e (n i v drift(i) - n e v drift(e-) ) = Σn(KE) e [(KE/e) (1 + cos 2  ) bxgradB /B 2 ] bxgradB/ B 2 = -3/rB i  at  = 0 soJ gc ~ -3n[ i + e ]/rB (for equatorial particles) I gc = ∫J gc dV /2  r ~ - 3E tot /(2  r2B) (b) From pressure gradient of gyrating particles J gradPperp xB = grad (n[ i + e ] perp.) I gradPperp ~∫rdrd  grad (n[ i + e ] perp.)/B ~ + E tot /2  r 2 B

72. so this (b) current reduces the average net ring current magnetic field by about 1/3. The net ring current then reduces the magnetic field at the magnetic equator at 1 R E by  B/B = - (2/3) E tot /E mag, where E mag is the volume-integrated energy in magnetic field. See more general derivation in R. L. Carovillano & J. J. Maguire, in Physics of the Magnetosphere, (Carovillano et al, ed’s), Reidel, 1968. Ring current usually peaks at 4-5 R E (quiet); at 2-4 R E (storm) Mean proton energy: 85keV (90% are in 10 - 250 keV) Quiet-time ring current density ~ 10 -8 A/m, increased by factor of several during storms. See Tascione sections 5.4.3, 5.9, 5.10

73. Typical energy spectrum of energetic protons

74. Power delivered by solar wind/ CME Power = Current x ∫(-vxB)dl Current varies as  c, i.e. as B Power varies as B 2 v sin 4 (  /2) where  = angle of IMF from northward sin = 0 for northward IMF sin = 1 for southward IMF J. K. Alexander, L.F. Bargatze, J. L. Burch et al., “Coupling of the solar wind to the magnetosphere” in Solar Terrestrial Physics D.M. Butler & K. Papadopoulos, ed’s. NASA, 1984 Tascione, sections 3.7, 5.8, 5.10

75. Energy injection into ring current Empirical approximate formula for ring-current addition rate in terms of Dst and ring-current- enhancement lifetime t: U R (J/hr) = 4x10 10 (dDst/dt + Dst/ t) (Tascione sec.5.10) See Akasofu [Sp. Sci Rev, 28, p160, 1981] for a related formula: |Dst| ~ 60*(log [epsilon] - 18)**2 + 25 where epsilon = B 2 v sin 4 (  /2)

76. Nov. 6, 2001 event Southward B component ~80 nT Unusually sharp CME shock with speed >1000km/s Nearly perpendicular shock L=8 SEP’s showed sharp rise in # on shock arrival L=3: 14-25 MeV protons arrived minutes before shock and were trapped when shock arrived via front-side & cusp entry stayed trapped til Oct ‘03 storm detrapped them 3-20 MeV electrons enhanced at first, but deep dropout of total >1MeV electron flux at L=3-8, with few-days recovery time

77. Mary Hudson’s PIC particle follower, riding on Fedder-Lyons-Mobarry MHD code, followed particles from ACE input data Cluster data (Morikis & Kistler, UNH) Cluster apogee 20 RE, perigee 4 RE, every ~48 hrs 50 hr orbit, 2hrs in magnetosphere at ~4RE Sampex data: ~1-3 MeV electrons, 10-20 MeV electrons

78. Stochastic Injection of Energetic Particles from Bow Shock and Tailward reconnection region Nonadiabatic because gyroradius ~ B scale-length locally Timescale  varies as  5/4  -1/2 Flux density injected varies as density at low densities M. G. Rusbridge, “Non-adiabatic effects in charged-particle motion near a neutral line”, Plasma Physics 19, 1087 (1977) and “Non-adiabatic charged particle motion near a magnetic field zero line”, Plasma Physics 13, 977 (1971) W. Peter & N. Rostoker, “Theory of plasma injection into a magnetic field”, Phys. Fluids 25, 730 (1982) J. Chen & P. J. Palmadesso, “Chaos and nonlinear dynamics of single-particle orbits in a magnetotail-like magnetic field”, JGR 91, 1499 (1986); errata 91, 9025 (1986)

79. Particle Diffusion Dominated by field fluctuations in storm conditions. Lee/Sydora Gyrokinetic Code calculates for Tokamaks. Diffusion model: W. N. Spjeldvik, “Consequences of the duration of solar energetic particle-associated magnetic storms on the intensity of geomagnetically trapped protons”, in Modeling Magnetospheric Plasma, T.E. Moore & J.H. Waite, ed’s. AGU 1988 J.M. Cornwall, “ Radial diffusion of ionized helium and protons: a probe for magnetospheric dynamics” JGR 77, 1756 (1972) df/dt = L 2 d/dL (D LL L -2 df/dL) - Af + G  -1/2 df/d  A = charge exchange factor, G = Coulomb slowing D LL (L,  ) given in Cornwall (1972), assumes power-law (  -2 ) spectrum of fluctuations in B and E.

80. Flow dynamics of charge-neutralized plasma fluid: [∂ t + Ugrad]U = (1/  o )[(Bgrad)B - grad(B 2 /2)] - (1/r) divP + g P = pressure tensor = p perp I + (p par - p perp )bb (div P ) perp = grad perp p perp - (p par - p perp )(bgrad)b (div P ) par = (bgrad)p par + (p par - p perp )divb div P = gradp for isotropic pressure [∂ t + Ugrad] (p perp /  B) = 0 [∂ t + Ugrad]( p par B 2 /  3 ) = 0 G.F. Chew, M.L. Goldberger, & F.E. Low, Proc. Roy. Soc (Lon.) A236, 112 (1956) N.A. Krall & A.W. Trivelpiece, Principles of Plasma Physics, McGraw Hill 1973

81. Magnetosphere Simulation Particle codes, incl. gyro-averaged particle followers ( e.g. Mary Hudson’s at NASA & R. M. Winglee code at UW ) Fluid (MHD) codes –Fedder-Lyon-Mobarry code (NRL) –BATSRUS (U. Michigan) –Spicer code(s): Odin etc. –Modified MHD: Winglee Hybrid (particles and MHD) codes –Rice MSM code –Kazeminezhad 2D code

82. Models are available for community use: –CCMC: http://ccmc.gsfc.nasa.gov/http://ccmc.gsfc.nasa.gov/ –UCLA: http://www-ggcm2.igpp.ucla.edu/http://www-ggcm2.igpp.ucla.edu/ Source codes in public domain: –GEDAS (Japan, T. Ogino) (Japan, T. ) http://gedas22.stelab.nagoya- u.ac.jp/simulation/jst2k/hpf02.html http://gedas22.stelab.nagoya- u.ac.jp/simulation/jst2k/hpf02.html –BATSRUS: http://csem.engin.umich.edu/http://csem.engin.umich.edu/ –NRL: http://www.lcp.nrl.navy.mil/hpcc-ess/software.htmlhttp://www.lcp.nrl.navy.mil/hpcc-ess/software.html FCTMHD3D (C.R. DeVore) AMRMHD3D (P. MacNeice) –Zeus 3D MHD (Michael Norman): http://zeus.ncsa.uiuc.edu:8080/lca_intro_zeus3d.html http://zeus.ncsa.uiuc.edu:8080/lca_intro_zeus3d.html –CFD Codes: http://icemcfd.com/cfd/CFD_codes.htmlhttp://icemcfd.com/cfd/CFD_codes.html

83. Fedder-Lyon-Mobarry (FLM) Code: distorted spherical coord. grid

84. MHD eqns as solved in FLM code J. G. Lyon, “Numerical methods used…”, Proc. ISSS-7, 26-31 March 2005

85. FLM Code Does not include particle acceleration (since it’s an MHD code) but does show overall energetics of CME coupling for southward IMF, and shows very weak coupling for northward IMF. Coupling is by fast magnetosonic wave propagation from magnetopause. Shows Poynting vector energy flow from these waves.

86. BATS-R-US Code (U. Mich.) Block-Adaptive-Tree Solarwind Roe-Upwind Scheme) Gombosi et al 3D MHD, Eulerian xyz grid (x toward sun) Block-adaptive mesh refinement Cell-centered finite volume method Upwind-differencing Riemann solver (Powell 1994) Efficiently parallelized High computation/communication ratio

87. Runs on Sun, SGI shared memory, Cray T3D & T3E, and IBM SP2 Simulation box typically 192 R E wide, +192 to -384 R E in x direction Cell size typically.25 R E to 32 R E Inner boundary at 3 R E (no mass flow across it) coupled along assumed dipole B lines to finite tensor conductivity, height- integrated ionosphere layer at 1 R E [M. L. Goodman, Ann. Geophys. 13, 843 (1995)] Dipole inner field separated off [as in Tanaka, JGR 100, 12057 (1995)]

88. BATSRUS simulation of outermost closed B lines, for Parker spiral IMF

89. Winglee modified MHD code R.M. Winglee, “Regional Particle simulations and Global Two-fluid Modeling of Magnetospheric Current Systems”, in J. L. Horowitz et al., Cross Scale Coupling in Space Plasmas, QC 809.P5 C76, 1995 Uses a 2-fluid modified MHD set of equations Gets the injection of currents & plasma across B-field lines

90. Rice MSM Code

91. E. C. Roelof, B. H. Mauk, R. R. Meier, K. R. Moore, & R. A. Wolf, “Simulation of EUV and ENA magnetospheric images based on the Rice Convection Model”, in Instrumentation for Magnetospheric Imagery II, SPIE 1993. (ENA = energetic neutral atom) Streamlined version of RCM = MSM (magnetic specification model), has non-self-consistent E field from “phenomenological convection patterns”.

92. F. Kazeminezhad new code 2D hybrid Triangular finite-element grid

93. MagnetoTail

94. Magnetic Reconnection

95. Modeling driven reconnection

96. 2-D Compressible Resistive MHD Simulation of Driven Reconnection S. -P. Jin & W. -H. Ip, Phys. Fluids B3, 1927 (Aug. 1991) Plasma beta at inflow boundary of simulation box: initially 0.1 Alfven Mach # of inflow: M A = 0.15 (for -.5 1 High Lundquist Number: 400 - 2500 (very low resistivity) –Lundquist Number = ratio of JxB force to resistive mag. diffusion force Initial B z (x) profile: half sine wave -w w (odd function of x) Initial state in pressure balance Grid resolution in x:  x increases 13% every step. Grid concentrated in center near x = 0. Time in units of Alfven-wave x-crossing time. Sim. ~ 40 units. Implicit integration scheme: Y. Q. Hu, J. Comp. Phys 84, 441 (1989)

97. B lines, v vectors,  T(%),  (%) S-P. Jin & W-H. Ip. 2D compressible MHD sim., PhysFluids B 3, 1927 (1991) Time ↓

98. PIC simulation of particle orbits near a magnetic reconnection line H-J. Deeg, J.E. Borovsky & N. Duric, Phys Fluids B 3, 2660 (1991) Geometry and results shown in following slides

99. Region where “magnetic insulation” fails, i.e where B is weak H-J. Deeg, J.E. Borovsky & N. Duric, Phys Fluids B 3, 2660 (1991)

100. Geometry for PIC simulation of particle acceleration near reconnection region H-J. Deeg, J.E. Borovsky & N. Duric, Phys Fluids B 3, 2660 (1991)

101. Proton orbits in views 1 & 2

102. Proton orbit in views 2 & 3

103. Energy gain of protons entering near neutral point H-J. Deeg, J.E. Borovsky & N. Duric, Phys Fluids B 3, 2660 (1991)

104. Final proton energy vs initial proton energy, for protons initially incoming near neutral point H-J. Deeg, J.E. Borovsky & N. Duric, Phys Fluids B 3, 2660 (1991)

105. Turbulence in B-line reconnection Matthaeus & Lamkin, PhysFluids 29, 2513 (1986) Contours of constant J Magnetic field Fluid stream- lines Contours of constant vorticity

106. Disturbed magnetotail reconnection at current sheet can launch plasmoids & relax (as well as accelerating particles forward & backward) E. W. Hones, Sci. Am. March 1986

107. Some references on field-line reconnection Observations by Cluster satellite: A. Runov et al., Geophys. Res. Lett. 30, 1579 (2003) Observations by WIND satellite: T. D. Phan et al., Nature 404, 848 (2000) ; M. Oieroset, R. P. Lin et al., Nature 412, 414 (2001) 3D PIC simulation: P.L. Pritchett & F. Coroniti, JGR 109, A 01220 (2004) 2D simulation with “guide field” normal to plane: P. L. Pritchett (UCLA): “Onset & Saturation of Guide-field Magnetic Reconnection”, Phys. Plasmas 12, 062301 (June 2005)

108. More references on field-line reconnection Particle acceleration & orbits: H-J Deeg, J.E. Borovsky & N. Duric (LANL), “Particle acceleration near X-type magnetic neutral lines”, Phys. Fluids B 3, 2660 (1991) Electric field enhancements (EFE): J. D. Scudder & F. S. Mozer, “Electron demagnetization and collisionless magnetic reconnection in  <<1 plasmas”, Phys. Plasmas 12, 092903 ( Sept. 2005) Role of microinstabilities (anomalous resistivity): M. Ugai & L. Zheng, “Conditions for fast reconnection mechanism in 3D” Phys. Plasmas 12, --- ( Sept. 2005)

109. Satellite sensors Radiation Belt Mappers GOES (ESA) Cluster, Vortex Doublestar Polar Image Geotail (Japan) ISEE1-3, IMP1-8 & other former sats with elderly data Ionospheric satellites measuring energetic particles: DMSP, SAMPEX etc. Upcoming: NPOESS & NPP

110. Living With A Star Research Network Solar Dynamics Observatory Pole Sitter Radiation Belt Mappers Ionospheric Mappers L 1 Solar Sentinel L2L2 Distributed network of spacecraft providing continuous observations Geospace Dynamics Nework with constellations of smallsats in key regions of geospace.

111. How to find satellite orbit info (& related data) http://pwg.gsfc.nasa.gov/orbits /menu_orbits.html Orbits for Wind, ISTP, Cluster, Image, Polar

112. Radiation Belt Mappers Understand origin and dynamics of the radiation belts. Determine time & space-dependent evolution of penetrating radiation during magnetic storms. First Element: multiple spacecraft in 3 petal equatorial orbits; in-situ measurements. Second Element: Add higher latitude coverage.

113. GOES description GOES (Geostationary Operational Environmental Satellites, NOAA/NESDIS) 2 spacecraft at 75deg W and 135deg W, one at 98deg W and/to 108deg W, moved with season. 35,600 km equatorial orbit, spin axis parallel to earth’s spin axis. Telemetry to NOAA ERL, Boulder. measuring: solar X-rays, B field at satellite, high energy particles, via SEM (Space Environment Monitor). SEM has (a) Total Energy Detector (TED)- intensity of energetic particles 0.3- 20 keV in 11 bands; (b)Medium-Energy Proton & Electron Detector (MEPED) - 30 keV- 60MeV; (c) High-Energy Proton & Alpha Detector (HEPAD) - 370 MeV- >850 MeV.

114. Cluster & Vortex

115. Cluster & Doublestar (DSP)

116. Cluster data (Morikis & Kistler, UNH) Cluster: (ESA & NASA, 2000) Cluster apogee 20 RE, perigee 4 RE, every ~48 hrs 50 hr orbit, 2hrs in magnetosphere at ~4RE

117. Some Cluster results Cluster has now proven the existence of The Kelvin-Helmholtz instability as an important solar wind entry process. These large-scale vortices could lead to substantial entry of solar wind to populate the Earth's magnetosphere. (Tai Phan, UCB SpSciLab.)

118. Polar: orbit (http://pwg.gsfc.nasa.gov/orbits/aaareadme_polarpar.html The POLAR orbital parameter plots show the radial distance, eccentric dipole (ED) magnetic local time (MLT), and eccentric dipole L-shell value. The darker segments correspond to times when one of the magnetic footpoints (traced down to 100 km altitude using the T89, Kp=3-,3,3+, model) falls in one of the following regions: cusp, cleft, or auroral oval.

119. Polar: observation of an event Images in visible light from the Polar satellite's Visible Imaging System compares the northern auroral regions on May 11, 1999, and a more typical day on November 13, 1999. Credit: University of Iowa/NASA.

120. Polar, cont’d May 11, 1999 event: solar wind flux dropped a lot produced an intense "polar rain" of electrons over one of the polar caps of Earth. Electrons flow unimpeded along the Sun's magnetic field lines to Earth and precipitate directly into the polar caps, inside the normal auroral oval. Such a polar rain event was observed for the first time in May 1999 when Polar detected a steady glow over the North Pole in X-ray images. Jack Scudder, U. Iowa, PI for the Hot Plasma Analyzer on NASA's Polar spacecraft. Scudder and Don Fairfield of Goddard had predicted the details

121. In parallel with the polar rain event, Earth's magnetosphere swelled to five to six times its normal size. NASA's Wind, IMP-8, and Lunar Prospector spacecraft, the Russian INTERBALL satellite and the Japanese Geotail satellite observed the most distant bow shock ever recorded by satellites. SAMPEX spacecraft reveal that in the wake of this event, Earth's outer electron radiation belts dissipated and were severely depleted for several months afterward.

122. Image Satellite ENA sensors

123. Image website (Southwest Research) http://pluto.space.swri.edu/IMAGE/ HENA: D. G. Mitchell and HENA team, the Johns Hopkins University Applied Physics Laboratory MENA: C. J. Pollock and J.-M. Jahn, Southwest Research Institute

124. HENA Images of ENA fluxes during the July 15-16 2000 Geomagnetic Storm

125. Geotail (Japanese space program) Instruments: Solar wind, hot plasma, & composition analyzers, directional data on electrons/protons/helium above 20keV, protons above 400keV, electrons above 120kev, B field, etc. http://www- istp.gsfc.nasa.gov/istp/geotail/geotail_key_para meters.html

126. DMSP Satellites: Orbits: circular, sun-synchronous, polar, ~850km alt. 98.7 deg inclination, period 101 min., revisit time 6 hrs. Global coverage @ 12hrs each satellite Communications: S-band, about 3 MBPS in 1995; maybe more capacity now. Design life: 3-5 yrs. Block(group) 5D-2 (5 sats) launched 1991-98, earlier ones presumably now down or inoperative; Block 5D-3 (5 more satellites, S16-20, built by Martin Marietta) launched 1999-06; Block 6 beginning 04.

127. DMSP, cont’d. Relevant sensors for space weather: SSI/ES Ionospheric Plasma Drift/Scintillation Monitor: 4 sensors monitoring ion & electron densities, temperatures, drift velocities of ions, and plasma irregularities above the F region. SSI/ES-2, 3 are enhanced versions, flown since ‘94 and ‘99. SSJ/4 Precipitating Electron/Proton Spectrometer SSB/X: X-ray detector array - x-rays from earth’s atmosphere. Upgraded version SSB/X-2 can also detect gamma ray bursts. SSM: magnetometer measures B-field fluctuations due to hi-latitude ionosphere currents.

128. Sampex (GSFC) Solar Anomalous and Magnetospheric Particle Explorer (Medium Earth Orbit). First of NASA's Small Explorer (SMEX) missions. Typical orbit: 520 x 670 km, 82 deg inclination Energy, composition and charge states of : (1) cosmic rays (2) solar energetic particles (3) magnetospheric electrons trapped by the Earth's magnetic field). http://www.astronautix.com/craft/sampex.htm etc. Sampex data: ~1-3 MeV electrons, 10-20 MeV electrons PET: Proton-Electron Telescope: energy spectra of electrons from 0.5 to 30 MeV, and of H and He from ~ 20 to 200 MeV/nuc http://www.srl.caltech.edu/sampex/

129. Upcoming: NPP & NPOESS The NPP satellite is scheduled for launch in 2007 into a circular sun-synchronous polar orbit at a nominal altitude of 824 kilometers and a 10:30 a.m. descending node. This orbit provides a 16-day repeat cycle (8-day quasi-repeat), similar to that of the EOS satellites. Ref.:The NPOESS Preparatory Project: Architecture and Prototype Studies (Aerospace Corp. website) The National Polar-orbiting Operational Environmental Satellite System (NPOESS) represents a convergence of systems previously operated by the Department of Defense and the National Oceanic and Atmospheric Administration (NOAA). Scheduled for launch in 2009, it will support a broad range of activities in global environmental monitoring, meteorology, and climatology.

130. NASA CDAW at GMU, Mar. 2005 http://cdaw.gsfc.nasa.gov/geomag_cdaw /register/wg2_participants.html Names & contact information of researchers in magnetosphere dynamics & data http://solar.scs.gmu.edu/meetings/cdaw/data/ cdaw2/wg2_datatable.htm Data files for selected events, from several satellite instruments (click on “data” & first “WG2 data table”)

131. Magnetosphere Homework Assignment, 10/25/05 1. Look up typical magnetotail storm-period data (Bfield strength, particle densities, particle “temperatures”) from, e.g., IMP 8 data. 2. Use these data along with Fig. 5.6 of Tascione to estimate the order of magnitude of: (a) tailward speed of ejected plasmoid (km/s) (b) directed particle energy of tailward-ejected plasmoid (J) (c) kinetic power loss (mean particle energy loss rate) during plasmoid ejection (W) (d) magnetic energy stored in magnetotail (J) 3. Use ACE or WIND data to estimate the typical order of magnitude of CME ram pressure rv 2 (J/m 3 ) and of CME-enhanced power delivery to day-side magnetopause (W), for southward B z = - 80nT and twice the typical Parker-spiral westward B y. Is this pressure much bigger than the magnetic field pressure? Estimate the power (W) delivered into the magnetopause by such a CME. 4. Tascione problem 5-4 5. Tascione problem 5-5 6. Tascione problem 5-12

132. CSI 769 Class Project, fall 2005 Magnetosphere portion: This part of the project focuses on the energetics of the Halloween ‘03 CME-induced changes in the magnetosphere, by doing five short order-of-magnitude calculations based on retrieved data. 1. From Wind or ACE data, estimate the peak CME (particle + magnetic) pressure increase on the bow shock, and its rise rate during the Halloween ‘03 event. 2. From earthbound magnetometer data, e. g. Dst, estimate (a) the time delay of surface  B after the bow-shock energy delivery, and (b) the energy and power delivery to the enhanced ring current during the storm. (c) If the time delay is related to propagation of a disturbance at near the Alfven speed, use the magnitudes of B and estimated plasma densities to compare the time delay to that of the most direct delivery route. (d) Is the ratio of estimated change in ring-current energy (volume integral of  KE +  (B 2 /2  o )) to CME energy (magnetopause-intersecting volume integral of energy density in the CME on bow-shock arrival) of order unity or <<1? 3. (a) Based on your estimates of magnetospheric  B due to enhanced ring current and its risetime, estimate the peak E fields (mV/m) induced, and compare them to the corotation E field. (b) Give an estimate of the peak E field on the topside of the ionosphere, say at 500km altitude, and the ExB drift speed E/B (km/s) at 60degrees magnetic latitude. 4. Use geotail data during the storm to estimate the peak change in magnetic energy storage in the magnetotail volume, and its buildup rate. Compare these numbers with the estimated frontside energy arrival by the CME. 5. Use NOAA energetic-particle flux data etc. to estimate the change in total energy in MeV (and higher- energy) protons transported by the storm to the auroral ionosphere, and compare this with the other energies calculated above. Part of the data is collected at “http://solar.scs.gmu.edu/meetings/cdaw/Data_master_table.html”

133. Some textbook errata Tascione Eq. 1.17: = (not +) after first term Eq. 1.33:B(vector)x gradient of scalar B (magnitude of vector B), not of vector B. Fig. 2.6:protons don’t arrive with predominantly 45 degree Incidence, even though B does. Water-sprinkler effect. p. 35:U components: theta & phi here are interchanged from the usual (i.e. Jackson). p.38 Eq 3.28:factor of d is ignored in the final proportionality and is treated as constant in 3.29, but reappears as L o 2 in 3.30. p.44 Eq. 4.9:Z on left, not H. Eq. 4.10:B on left, not H. p. 59 Eq. 5.20:+ sign (not -) in numerator.

134. Some textbook errata, cont’d. Parks p. 56 Eq. 3.36 & 3.37: Confused notation. r and lambda are component indices, not independent variables. p. 72 Eq. 3.73: Careful! The rotation axis is not the magnetic axis. See Tascione Eq’s 4.1 & 4.2. p. 106, first line of sec. 4.55.6: current density, not currents. Current is meaningful for single charged particle in motion (I=qv). Current density is not p. 139 problem 18: dimensional error in formula. p. 156, top two eq’ns: either one or the other (not both, unless gamma = 1). p. 249 Eq. 7.20: see eq. 7.57 when p is anisotropic. p.255 below eq. 7.39: “outward” = out of paper (as looking down from N pole), not radially outward from earth. p. 259 after eq. 7.53: del parallel plus del perp. (not -) p.261 after eq. 7.65: B is not necessarily given, just static. p.264 after eq. 7.70: B r vanishes at the magnetic equator (only). p.265 eq. 7.74: sum over species! Epsilon is the energy-density of all the drifting particles (e + i). p.267 Eq. 7.82: delta B T /B s on left side, not delta B T. p. 314, before sec. 8.2.2: Plasmas in steady state do support free charges, but mainly at or near their boundaries. Like a pretty-good conductor, they move the net charge to the ‘surface”.